1. Field of the Invention.
This invention relates generally to wastewater treatment systems which biologically treat wastewater and, more particularly, to biological treatment systems which utilize floating filter media to biologically treat wastewater.
2. Prior Art.
In high density aquaculture systems, such as catfish farms, and in other water systems which generate wastewater, it is necessary to remove suspended solids, optimize nitrification and to reduce biochemical oxygen demand (BOD) of the wastewater. In all cases, treated water is eventually returned to the ecosystem, whether the return is to a lake or stream or back to a controlled aquaculture system. Varying load and flow conditions make operation of waste treatment systems difficult, in that the timing of treatment steps is dependent upon such changing conditions.
In the operation of any wastewater treatment system, it is desirable to waste as little water as possible and to maximize the concentration of waste sludge accumulated by the system. This is especially true in high density aquaculture systems, where constant recirculation of water is necessary, and where it is desirable to minimize the amount of water wasted in the treatment process. Most prior art systems accomplish treatment using various traditional treatment components, such as aeration basins, filters and clarifier units, with each component having its own treatment and energy consumption limitations. A system which efficiently combines the features of separate component systems would have greater advantages over those presently in use.